This invention arose from an effort to eliminate the need for special purpose tools when reassembling an automobile differential after substituting new axial thrust bearing assemblies within it. This task typically requires special factory-supplied tooling, or tedious trial and error methods that require visual matching of gear tooth patterns. As in many other gear applications, it is most important that the meshing gears be reassembled in precisely the positions in which they have been previously used, or undesirable wear and noise will result during subsequent usage.
The present fixture enables the user to accurately compare the thickness of any axially shimmed bearing assembly to the thickness of a reference bearing assembly. It is designed specifically for use in conjunction with conical axial thrust bearings, which cannot be axially measured by hand, since the bearing elements are not self-aligning and must be compared in thickness under normal axial thrust loading conditions.
The fixture accommodates all the variables that occur in replacing shimmed axial thrust bearings, including minor differences in shim thickness, and mismatches between a bearing and a race. Mismatches are very frequent, since the bearings and races are typically distributed separately from one another. In many instances, each might be produced by a different manufacturer.
The present fixture provides a comparison of the axial thicknesses of two bearings with or without shims to enable a user to select the required replacement bearing and shim thickness. It enables the user to accurately select a new shim combination which will axially locate the bearing to match the previous position of the bearing in the assembled machinery. It eliminates trial and error and overcomes the usual difficulties encountered in pressing shims and/or bearings onto and from a mounting shaft. The comparison of the bearing assembly thickness can be accomplished independently of any shaft assembly, so that the final shimmed bearing assembly can be utilized with a high degree of confidence.